Q64.If a1, a2, a3, . . . . are in A.P. such that a1 + a7 + a16 = 40, then the sum of the first 15 terms of this A.P is: (1) 280 (2) 120 (3) 150 (4) 200
What This Question Tests
This question tests the basic properties of an arithmetic progression, specifically relating the sum of certain terms to the sum of the first 'n' terms using common difference and first term.
Concepts Tested
Formulas Used
an = a + (n-1)d
Sn = n/2 * (2a + (n-1)d)
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📋 Question Details
- Chapter
- Sequences & Series
- Topic
- Arithmetic Progression (AP)
- Year
- 2019
- Shift
- 12 Apr Shift 2
- Q Number
- Q64
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 9: Sequences and Series
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